Getting ready for a presentation may cause feelings of anxiety. the best way to reduce your fears is to prepare thoroughly. the first step in being well prepared for a presentation is planning. why is determining your purpose the most important part of preparation

I believe the answer is: knowing your purpose

By knowing your purpose, you could determine the type of approach that would be best for the presentation, the target audience that you should seek and the type of material you could give in order to make sure that the audiences receive the full message of the presentation.